Investigation Into the effect of Temperature on Respiration
Scientific Knowledge
'Respiration is the process in which organic molecules act as fuel' (from Central concepts by Mary Jones and Jennifer Gregory). Respiration is needed to produce ATP. ATP is an immediate and universal state of energy for cells. It is made available for use in the living cell by respiration. Respiration takes place in the mitochondria in the cell. A series of oxidation and reduction reactions take place, in which respiratory substrates (glucose is the major respiratory substrate) are oxidised to carbon dioxide, and oxygen reduced to water. You can measure the rate of respiration by collecting carbon dioxide. Here is an explanation of respiration to show why this method can be used. Glucose is a relatively large molecule containing six carbon atoms, all in reduced state. During respiration glucose undergoes a series of enzymes catalysed oxidation reactions. These reactions occur in three main stages: Glycolysis, the Krebs cycle and the electron transfer chain. 'Glycolysis is a series of reactions in which six-carbon sugar is broken down to two molecules of the three-carbon pyvurate ion' (from Advanced Biology by John Murray). The process of glycolysis are common to both anaerobic and aerobic respiration.
After glycolysis takes place, the product pyvurate enters the mitochondria. It is then decarboxylated (by removal of carbon dioxide). The two remaining carbons react with coenzyme A to form acetylcoenzyme. Simultaneously hydrogen ions are transferred to the hydrogen acceptor NAD, which forms NADH. AcetylCoA reacts with oxaloacetate (4C). This reaction is caused by enzymes. The acetyl groups splits off, citrate (6c) is formed and coacetylcoenzyme A is released for reuse. In a series of reactions the citrate is converted back to oxaloacetate, which becomes available to repeat cycle. At certain points on the cycle two molecules are given off. This can be collected to measure the rate of reaction. A pair of hydrogens are removed and a molecule of ATP is made. The hydrogen atoms taken up by NAD, with the exception of one pair that is, are directly attached to FAD.
The pairs of hydrogen atoms are removed from respiratory intermediates during the oxidation of glucose, and are accepted by a hydrogen acceptor; usually NAD.The dehydrogenation reactions are catalysed by enzymes known as dehydrogenases. The hydrogen atoms in NADH are ultimately oxidised in water by oxygen in a process involving several intermediate steps. This process is known as the electron transport pathway. 'At three points of transfer in the chain, energy is released and is used inn synthesis of ATP from ADP and phosphate in the present of the ATP-synthase enzyme' (from Advanced Biology by John Murray).
Scientific Knowledge
'Respiration is the process in which organic molecules act as fuel' (from Central concepts by Mary Jones and Jennifer Gregory). Respiration is needed to produce ATP. ATP is an immediate and universal state of energy for cells. It is made available for use in the living cell by respiration. Respiration takes place in the mitochondria in the cell. A series of oxidation and reduction reactions take place, in which respiratory substrates (glucose is the major respiratory substrate) are oxidised to carbon dioxide, and oxygen reduced to water. You can measure the rate of respiration by collecting carbon dioxide. Here is an explanation of respiration to show why this method can be used. Glucose is a relatively large molecule containing six carbon atoms, all in reduced state. During respiration glucose undergoes a series of enzymes catalysed oxidation reactions. These reactions occur in three main stages: Glycolysis, the Krebs cycle and the electron transfer chain. 'Glycolysis is a series of reactions in which six-carbon sugar is broken down to two molecules of the three-carbon pyvurate ion' (from Advanced Biology by John Murray). The process of glycolysis are common to both anaerobic and aerobic respiration.
After glycolysis takes place, the product pyvurate enters the mitochondria. It is then decarboxylated (by removal of carbon dioxide). The two remaining carbons react with coenzyme A to form acetylcoenzyme. Simultaneously hydrogen ions are transferred to the hydrogen acceptor NAD, which forms NADH. AcetylCoA reacts with oxaloacetate (4C). This reaction is caused by enzymes. The acetyl groups splits off, citrate (6c) is formed and coacetylcoenzyme A is released for reuse. In a series of reactions the citrate is converted back to oxaloacetate, which becomes available to repeat cycle. At certain points on the cycle two molecules are given off. This can be collected to measure the rate of reaction. A pair of hydrogens are removed and a molecule of ATP is made. The hydrogen atoms taken up by NAD, with the exception of one pair that is, are directly attached to FAD.
The pairs of hydrogen atoms are removed from respiratory intermediates during the oxidation of glucose, and are accepted by a hydrogen acceptor; usually NAD.The dehydrogenation reactions are catalysed by enzymes known as dehydrogenases. The hydrogen atoms in NADH are ultimately oxidised in water by oxygen in a process involving several intermediate steps. This process is known as the electron transport pathway. 'At three points of transfer in the chain, energy is released and is used inn synthesis of ATP from ADP and phosphate in the present of the ATP-synthase enzyme' (from Advanced Biology by John Murray).
